Research On Modeling And Optimization Design Method Of Smart Meter Load Switch

The smart meter load switch includes a built-in load switch and an external load switch,which are key components for realizing remote power control of low voltage users.The meter load switch has a complicated working environment,large temperature and humidity,and narrow space.The failure caused by the quality problem of the meter load switch accounts for about 50% of the failure of the smart meter.Failure of the meter load switch can lead to safety accidents such as electric shock,fire and explosion,resulting in personal injury and major economic losses.Therefore,the paper analyzes the various failure causes of the meter load switch,studies various failure mechanisms caused by various factors in the life cycle,optimizes the design of the meter load switch,and ensures its safe and stable operation,which have gradually become the focus of research at home and abroad in recent years.Based on the key scientific and technological projects of the State Grid Corporation,this dissertation has carried out the theory and technology research on the modeling and optimization design method of smart meter load switch.The theoretical analysis,method design and experimental verification of the static suction reaction model and the static and dynamic calculation method of the built-in load switch of the meter are carried out.Aiming at the key parameters of the built-in load switch,the quality characteristic optimization model based on double response surface is established,and the optimal parameter combination is obtained,which improves the comprehensive performance of the built-in load switch.The arc-extinguishing system of the external load switch is improved,the control and feedback unit was developed,and a new high-reliability external load switch was designed and implemented.The main research work and innovations of this dissertation mainly include:(1)Aiming at the quality characteristics of the built-in load switch of the smart meter,the equivalent magnetic circuit model of the built-in load switch considering the magnetic flux leakage and the static reaction force model of the contact spring system based on the deformation energy method are established,and the fast calculation method of the static suction reaction force characteristic is given.The quick calculation of the static suction reaction force characteristic of the built-in load switch is realized.Through the static simulation of the suction reaction force of ANSYS and ADMAS software,the correctness and accuracy of the rapid calculation model of the suction reaction force is verified.Aiming at the dynamic characteristics of the built-in load switch of the electric energy meter,the built-in load switch dynamic analysis model and the dynamic characteristic calculation analysis method based on the static suction reaction force data are given.The simulation results show that the dynamic characteristic analysis model can correctly reflect the armature stroke under dynamic conditions.Transitions with dynamic characteristics such as armature angular velocity and armature acceleration.(2)Using the static dynamic modeling and quick calculation method of the built-in load switch,the key design parameters of the load switch built in the power meter are analyzed.In order to improve the key indicators and performance of the built-in load switch of the electric energy meter,the optimization objectives,optimization methods and optimization steps of the quality characteristics based on the virtual sample are given.A dual-response surface model of the mass characteristics of electromagnetic suction force and reed-reaction force is established.The double-response surface model is used to fit the key parameters of the electromagnetic system and the contact spring system.Within the optimized boundary parameter range,a double response surface is adopted for the input parameters.The optimization model of quality characteristics is optimized to obtain the optimal combination of parameters.The results of optimization analysis show that this optimized design effectively improves the product’s electrical life,resistance to short-circuit current,and immunity to electromagnetic interference.(3)In view of the frequent failure of the external load switch of the electric energy meter and the serious shortage of arc extinguishing capability,the arc failure analysis and performance optimization research is carried out.Based on the analysis of the mechanism of arc-extinguishing failure of external load switch,the simulation model of external load switch failure is established.Based on the analysis of the simulation results,starting from the structure and material design of the arc chute,the upper slice and the lower slice,the comprehensive optimization design method for improving the arc extinguishing performance of the external load switch is given.The experimental models for electrical and short-circuit reliability of external load switches are established.The experimental results show that the integrated optimization design method can significantly improve the arc-extinguishing performance and breaking capacity of the external load switch,reduce the arc-breaking time and breaking time of the external load switch,and effectively improve the reliability and safety of the external load switch,effectively solves the problem of arc-extinguishing failure of external load switches.(4)In view of the problem that the low voltage load switch can not be opened and closed remotely and the status of feedback is accurately fed back,an intelligent external load switch control and state feedback system is designed.Based on the modular and platform design concept of hardware and software,the design of low power MCU system,low power consumption power supply design,DC motor condition monitoring and design,Charge and sub-gate control design,pay-switch control design,motor drive design,motor control process design and other key technologies.The system control and feedback test environment are set up.The experimental results show that the design of the control system is feasible and feasible,and it can realize the control of opening and closing and status feedback under different conditions and meet the standard requirements.